/**
 * AdminApplication - part of PerlaGis Architecture
 *
 * Copyright (C) 2010 Ricardo Gonzalez (gomnaz@gmail.com)
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see http://www.gnu.org/licenses/
 */
package org.admin.servlets;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.admin.controllers.PerlaController;
import org.apache.taglibs.standard.tag.common.core.NullAttributeException;
import org.perla.services.NoRelationException_Exception;
import org.perla.services.Relation;

/**
 * Servlet che gestisce le operazioni sulle relazioni.
 * In base al parametro <code>action</code> può eseguire le seguenti operazioni:
 * <ul>
 * <li><code>null</code> o </code>list</code>: restituisce la lista delle relazioni</li>
 * <li></code>create</code>: crea una relazione per il nodo Perla <code>idNodo</code>, con nome <code>nome</code> e notifica attiva se <code></code> è <code>true</code></li>
 * <li></code>remove</code>: rimuove la relazione relativa al sensore Gis <code>idSensore</code></li>
 * <li></code>change</code>: cambia il valore della notifica per la relazione relativa al sensore Gis <code>idSensore</code></li>
 * </ul>
 *
 * @author Ricardo Gonzalez
 * @author Eva Gjeci
 */
@WebServlet(name = "RelationActions", urlPatterns = {"/relation"})
public class RelationServlet extends HttpServlet {

    /** 
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/xml;charset=UTF-8");
        PrintWriter out = response.getWriter();
        String i = "";
        try {
            String action = request.getParameter("action");
            if (action == null) {
                action = "list";
            }
            if (action.equals("create")) {
                i = " ";
                if (!PerlaController.addRelation(request.getParameter("idNodo"), request.getParameter("nome"), Boolean.valueOf(request.getParameter("notifica")))) {
                    i = "<error><message>Insert failed</message></error>";
                }
            } else if (action.equals("remove")) {
                i = " ";
                String idSensore = request.getParameter("idSensore");
                PerlaController.removeRelation(idSensore);
            } else if (action.equals("change")){
                i = " ";
                if (request.getParameter("idSensore") == null){
                    throw new NullAttributeException("idNodo", "idNodo");
                }
                String idSensore = request.getParameter("idSensore");
                PerlaController.changeNotify(idSensore);
            } else if (action.equals("list")) {
                List<Relation> l = PerlaController.getRelations();
                for (Relation r : l) {
                    i += "<relation>"
                            + "<labelSensoreGis>" + r.getLabelSensoreGis() + "</labelSensoreGis>"
                            + "<idNodoPerla>" + r.getIdNodoPerla() + "</idNodoPerla>"
                            + "<idSensoreGis>" + r.getIdSensoreGis() + "</idSensoreGis>"
                            + "<lastUpdate>" + r.getLastUpdate() + "</lastUpdate>"
                            + "<notifica>" + r.isNotifica() + "</notifica>"
                            + "</relation>";
                }
            }
        } catch (NoRelationException_Exception ex){
            i = "<error><message>No relation</message></error>";
        }catch (NullAttributeException ex){
            i = "<error><message>No relation found</message><cause>empty value</cause></error>";
        } finally {
            if (i.equals("")) {
                i = "<error><message>Something appened</message></error>";
            }
            out.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?><root>" + i + "</root>");
            out.close();
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
